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Show 1875.] DR. J. S. B O W E R B A N K ON T H E SPONGIADcE. 281 the dermal rete with its central canals, and the smooth elongate-conical defensive organs, x 36 linear. Fig. 7. A small portion of the siliceo-fibrous skeleton of Farrea parasitica, X 80 linear. 2. Contributions to a General History of the Spongiada?. B y J. S. B O W E R B A N K , LL.D., F.R.S., & c - P a r t VII. [Eeceived March 12,1875.] When my friend Commodore Parish went out to China to take the command at Hong Kong, he kindly promised to render m e any assistance in his power in the collection of Sponges and other specimens of natural history; and I am pleased to say he has performed his promise in a most effective and liberal manner. By far the greater number of specimens of Sponges sent home to England are so carefully and effectually washed instead of being dried immediately in the condition in which they come from the sea, that the greater portion of their most valuable specific characters are completely destroyed. This destructive process has been carefully avoided in the preservation of the specimens which form the subjects of the present communication ; and the descriptions of these specimens are the more valuable to science as they lead us to the conclusion that the species at that distant portion of the earth are iu reality very closely allied in their generic and other anatomical characters to those of our Northern European seas. MICROCIONA TUBEROSA, Bowerbank. Sponge massive, sessile, tuberous; tuberous projections corrugated, minutely spinous, more or less fistulous. Oscula simple, small, dispersed. Pores inconspicuous. Dermal membrane pellucid, spiculous ; tension-spicula acuate, slender, dispersed, rather few in number. Skeleton-columns rather stout, anastomosing, forming a coarse, open, and somewhat complicated rete; skeleton-spicula acuate, rather long and slender ; internal defensive spicula attenuato-acuate, small, entirely spinous. Interstitial membranes spiculous ; tension-spicula slender, acuate, few in number. Colour, in the dried state, dull pale green. Hab. Straits of Malacca (Commodore Parish, R.N.). Examined in the dried state. This very remarkable sponge was sent to m e by m y friend Commodore Parish with several other interesting and valuable specimens collected in the Straits of Malacca. It is based on the surface of another species of sponge, a unispiculous Halichondria, which it almost entirely covers, and with which it is so intimately incorporated, and so closely resembles it in colour, as to render it very difficult to discriminate the two without a microscopical examination of their structures. Its external form is singular and very characteristic. It is 2 | inches long, l^ broad, 1| inch in height; and its external |